Controlled Flight into Terrain “American 965”

On Dec. 20, 1995, at 2142 EST, American Airlines Flight 965, a scheduled passenger flight from Miami (MIA) Florida, USA to Alfonso Bonilla Aragon International Airport (SKCL) in Cali, Colombia, operating under instrument flight rules (IFR) crashed into mountainous terrain during a descent from cruise altitude in visual meteorological conditions (VMC). The accident site was near the town of Buga, 33 miles northeast of the Cali VOR (CLO). The aircraft impacted terrain at about 8900 feet ASL, near the summit of El Deluvio and approximately 10 miles east of Airway W3. Of the 163 souls on board including 8 crew members, 4 passengers survived the accident.

Airfield information

Alfonso Bonilla Aragon Airport (SKCL) in Cali in the Cordillera Occidental is in a narrow valley oriented north to south. Mountains extend up to 14,000 feet MSL to the east and west of the valley. The airport is approximately 7.5 miles north of CLO, at an elevation of 3162 feet ASL. The approach is flown in the valley, and then via circling for Runway 01 after reporting over Rozo via Tulua.

The Tulua VOR (ULQ) was approximately 33 nautical miles north of the airfield (43 DME from CLO), and was the initial point depicted on the ROZO 1 arrival. The airport was served by Cali Approach. No approach control radar was available. The airport control tower operated 24 hours a day for arriving and departing traffic to runways 01 and 19.

Scheduled departure was 1640 but actual departure time was 1835. Estimated enroute time (EET) was 3 hours and 12 minutes. Cruise at FL370 (thirty-seven thousand feet above mean sea level). Route of flight from Miami is through the Cuban, Jamaican and into the Columbian airspace, where the flight was recleared by Barranquilla Centre to proceed from KILER intersection direct to BUTAL intersection. The flight then passed abeam Cartegena (CTG). Bogota Centre subsequently cleared the flight to fly direct from BUTAL to the Tulua VOR (ULQ).

Captain, 57. Total Time is 13,000 hours, 2260 hours on type B757/767. Flew 13 times into Cali before the accident flight of which the last two were on Dec 9 and 14, 1995. Described by colleagues as a non-smoker, in exemplary health and respected for his professional skills.

First Officer, 39. Total Time is 5800 hours, 2286 hours on type B757/767. With AA for 9 years, on first trip to Cali. Described by colleagues as professionally competent and appropriately assertive as a flight crew member.

The accident aircraft incorporated a flight management system (FMS) that included a flight management computer (FMC), a worldwide navigation data base that contained radio frequencies and latitude and longitude coordinates of relevant navigation aids as well as coordinates of airports capable of B-757 operations. The FMC data base also included B-757 performance data which combined with pilot inputs, governed autothrottle and autopilot functions. The FMS monitored the system and engine status and displayed the information, through electronically-generated cathode ray tube (CRT) displays. The pilot input into the FMS could be performed either through a key board and associated cathode ray tube (CRT), known as a control display unit (CDU), or through a more limited FMS input via controls on the glareshield panel.

Cali Approach (2136:01)-sir, the wind is calm, are you able to [execute the] approach [to] runway one niner?

AA965-uh yes sir, we’ll need lower altitude right away though.

Cali Approach-roger, American niner six five is cleared to VOR DME approach runway one niner, Rozo number one arrival, report Tulua VOR.

AA965-cleared the VOR DME to one nine, Rozo one arrival, will report the VOR, thank you sir.

Captain thinks he is cleared direct to Cali, but controller wants him to report Taluha (italics mine)

Cali Approach-report uh, Tulua VOR.

AA965-report Tulua.

AA965 (2137:29) Can American airlines uh, nine six five go direct to Rozo and then do the Rozo arrival sir?

Cali Approach-affirmative, take the Rozo one and runway one niner, the wind is calm.

AA965-alright Rozo, the Rozo one to one nine, thank you, American nine six five

Cali Approach-report Tulua and twenty-one miles ah, five thousand feet.

AA965-OK, report Tulua twenty-one miles and five thousand feet, American nine uh, six five.

At 2137, after passing ULQ (Tulua VOR position Flight Data Recorder based) during its descent, the aircraft to turn to the left of the cleared course and flew on an easterly heading for approximately one minute. Then the aircraft turned to the right, while still in the descent. At 2139:25, Morse code for the letters “VC was recorded by navigation radio onto the aircraft’s cockpit voice recorder. At 2139:29, Morse code similar to the letters “UL” was recorded.

AA965 (2140:01) and American uh, thirty-eight miles north of Cali, and you want us to go Tulua and then do the Rozo uh, to uh, the runway, right to runway one nine?

Cali Approach-you can [unintelligible word] landed, runway one niner, you can use runway one niner, what is [your] altitude and [the] DME from Cali?

AA965 Ok, we’re thirty-seven DME* at ten thousand.

*37 DME north of Cali VOR (CLO) places the aircraft 6 miles south of ULQ and 28 miles north of the approach end of runway 19 at Cali (SKCL).

Cali Approach (2140:25) roger, report uh five thousand and uh, final to runway one niner.

The CVR recorded the flight crews conversations as well as radio transmissions.

Captain to First Officer (2140:40) — is that [expletive] Tulua? I’m not getting for some reason, see I can’t get, OK now, no, Tulua [expletive] up.

Captain to First Officer (2140:49) but I can put in the box if you want it.

First Officer to Captain-I don’t want Tulua, lets just go to the extended centerline of uh . . .

Captain to First Officer-which is Rozo?

Captain to First Officer (2140:56) why don’t you just go direct to Rozo then, alright?

First Officer to Captain-Ok, lets

Captain to First Officer…am going to put that over you.

First Officer to Captain– get some altimeters, we’re out of uh, ten now.

At 2141:02, Cali Approach requested the flight’s altitude

AA965-nine six five, nine thousand feet.

Cali Approach (2141:10) roger, distance now?

The flight crew did not respond to the controller.

At 2141:15: the cockpit voice recorder (CVR) recorded from the cockpit area microphone the mechanical voice and sounds of the aircraft’s ground proximity warning system (GPWS), terrain, terrain, whoop, whoop.

The FDR showed that the flight crew added full power and raised the nose of the aircraft; the spoilers (speedbrakes) that had been extended during the descent were not retracted. The aircraft entered the regime of stick shaker stall warning, nose up attitude was lowered slightly, the aircraft came out of stick shaker warning, nose up attitude then increased and stick shaker was re-entered. The CVR ended at 2148:28.

The wreckage path and FDR data evidenced that the aircraft was on a magnetic heading of 223 degrees, nose up, and wings approximately level, as it struck trees at about 8900 feet above sea level on the east side of El Deluvio. The aircraft continue over the ridge near the summit and impacted and burned on the west side of the mountain, at North 03 degrees, 50 minutes, 45.2 seconds, latitude and West 76 degrees, 06 minutes and 17.1 seconds of longitude.

Findings

American Airlines provided training in flying in South America that provide flight crews with adequate information regarding the hazards unique to operating there

The AA965 flight crew accepted the offer by the Cali Approach controller to land on runway 19 at SKCL.

The flight crew expressed concern about possible delays and accepted an offer to expedite their approach into Cali

The flight crew had insufficient time to prepare for the approach to runway 19 before beginning the approach

The flight crew failed to discontinue the approach despite their confusion regarding elements of the approach and numerous cues indicating the inadvisability of continuing the approach

Numerous important differences existed between the display of identical navigation data on approach charts and on FMS-generated displays even though the same supplier provided AA with navigational data.

The AA965 was not informed or aware of the fact that the identifier that appeared on the approach (Rozo) did not correspond to the identifier (Romeo) that they entered and executed a FMS command.

FMC offered a list of so captain selected first on top of list. This is not cross checked with First Officer, provisional track showing left turn and back. First stands for Bogota, 132 miles behind them at 7 o’clock position. Aircraft starts going there.

italics mine

One of the AA965 pilots selected a direct course to the Romeo NDB believing that it was the Rozo NDB, and upon executing the selection in the FMS permitted a turn of the aircraft towards Romeo, without having verified that it was the correct selection and without having first obtained approval of the other pilot, contrary to AA’s procedures

The incorrect FMS entry led to the aircraft departing the inbound course to Cali and turning it towards the city of Bogota. The subsequent turn to intercept the extended centerline of runway 19 led to the turn towards high terrain

The descent was continuous from FL230 until the crash

Neither pilot recognized that the speedbrakes were extended during the GPWS escape maneuver, due to lack of clue available to alert them about the extended condition

The Cali approach controller followed applicable ICAO and Colombian air traffic control rules and did not contribute to the cause of the accident.

Probable Causes

Aeronautica Civil determines that the probable causes of this accident were:

The flight crew failure to adequately plan and execute the approach to runway 19 at SKCL and their inadequate use of automation

Failure of the flight crew to discontinue the approach into Cali, despite numerous cues alerting them of the inadvisability of continuing the approach.

The lack of situational awareness of the flight crew regarding vertical navigation, proximity to terrain, and the relative location of critical radio aids

Failure of the flight crew to revert to basic radio navigation at the time when the FMS-assisted navigation became confusing and demanded an excessive workload in a critical phase of the flight.

Contributing Factor

The flight crew’s ongoing efforts to expedite their approach and landing in order to avoid potential delays.

The flight crew’s execution of the GPWS escape maneuver while the speedbrakes remained deployed

FMS logic that dropped all intermediate fixes from the display (s) in the event of execution of a direct routing

FMS-generated navigational information that used a different naming convention from that published in navigational chart

American Airlines Flight 965 was a regularly scheduled flight from Miami International Airport in Miami, Florida, to Alfonso Bonilla Aragón International Airport in Cali, Colombia. On December 20, 1995, the Boeing 757-200 flying this route (registration N651AA crashed into a mountain in Buga, Colombia, killing 151 passengers and eight crew members. The crash was the first U.S.-owned 757 accident and the highest death toll of any accident in Colombia. It is also the highest death toll of any accident involving a Boeing 757 at that time. It was surpassed by Birgenair Flight 301 which crashed seven weeks later with 189 fatalities. Flight 965 was the deadliest air disaster involving a U.S. carrier since the bombing of Pan Am Flight 103 in 1988. Five passengers, all seated within two rows of each other, survived the initial impact, but one died two days later of his injuries.

The Colombian Special Administrative Unit of Civil Aeronautics investigated the accident and determined it was caused by navigational errors by the flight crew.

Aircraft

The aircraft was a Boeing 757-223 registered N651AA. Its first flight was on August 12, 1991, and was the 390th Boeing 757 built. The aircraft was powered by two Rolls-Royce RB211 engines.

Flight history

Departure

At that time, Flight 965 mainly carried people returning to Colombia for the Christmas holiday, vacationers and businesspeople. A winter storm in the northeast United States caused the airline to delay the departure of the airliner for thirty minutes to allow for connecting passengers to board the flight, so Flight 965 pushed back from the gate in Miami at 5:14 pm, and then taxied to runway 27R, but seasonal congestion caused the 757 to take off at 6:35 pm, 1 hour 21 minutes late. Some other passengers booked on Flight 965 missed the flight due to missed connections.

The cockpit crew consisted of Captain Nicholas Tafuri, age 57, and First Officer Donald Williams, age 39. Both pilots were highly skilled airmen. Captain Tafuri had more than 13,000 hours of flying experience and First Officer Williams had almost 6,000 hours. The cabin crew consisted of Purser Pedro Pablo Calle and Flight Attendants Magdalena Borrero, Rosa Cabrejo, Teresa Delgado, Gilberto Restrepo, and Margaret “Maggie” Villalobos. All cabin crew personnel were born in Colombia and were veterans from Braniff International Airways who had moved to Eastern Air Lines and then to American Airlines, when the routes were transferred from one airline to the other. They had voluntarily chosen the flight, as a prerogative awarded by seniority, to spend Christmas time with their families in Bogotá.

Going off-course

Cali’s air traffic controllers had no functional radar to monitor the 757, as it had been blown up in 1992 by the terror group FARC. Cali’s approach uses several radio beacons to guide pilots around the mountains and canyons that surround the city. The airplane’s flight management system already had these beacons programmed in, and should have, in theory, told the pilots exactly where to turn, climb, and descend, all the way from Miami to the terminal in Cali.

Since the wind was calm, Cali’s controllers asked the pilots whether they wanted to fly a straight-in approach to runway 19 rather than coming around to runway 01. The pilots agreed, hoping to make up some time. The pilots then erroneously cleared the approach waypoints from their navigation computer. When the controller asked the pilots to check back in over Tuluá, north of Cali, it was no longer programmed into the computer, and so they had to pull out their maps to find it. In the meantime, they extended the aircraft’s speed brakes to slow it down and expedite its descent.

By the time the pilots found Tuluá’s coordinates, they had already passed over it. In response to this, they attempted to program the navigation computer for the next approach waypoint, Rozo. However, the Rozo NDB was identified as R on their charts. Colombia had duplicated the identifier for the Romeo NDB near Bogotá, and the computer’s list of stored waypoints did not include the Rozo NDB as “R”, but only under its full name “ROZO”. In cases where a country allowed duplicate identifiers, it often listed them with the largest city first. By picking the first “R” from the list, the captain caused the autopilot to start flying a course to Bogotá, resulting in the airplane turning east in a wide semicircle. By the time the error was detected, the aircraft was in a valley running roughly north-south parallel to the one they should have been in. The pilots had put the aircraft on a collision course with a 3,000-meter (9,800 feet) mountain. The air traffic controller, Nelson Rivera Ramírez, believed that some of the requests of the pilots did not make sense, but did not know enough non-aviation English to convey this.

Crash

Twelve seconds before the plane hit the mountain, named El Diluvio (The Deluge), the Ground Proximity Warning System activated, announcing an imminent terrain collision and sounding an alarm. Within a second of this warning the first officer disengaged the autopilot, and the captain attempted to climb clear of the mountain; however, neither pilot had remembered to disengage the previously deployed speed brakes, which reduced the rate of climb. At 9:41:28 pm Eastern Standard Time it struck trees at about 8,900 feet MSL on the east side of the mountain. The crash was six miles south of Tuluá VOR and 28 miles north of the approach end of runway 19 at Alfonso Bonilla Aragon International Airport. During the investigations, it was found that neither the Boeing fixed-base simulator nor the CDU/FMS simulator could be back driven with the data obtained directly from the accident airplane’s flight data recorder. Because the B-757 flight simulators could not be back driven during the tests, it could not be determined with precision whether the airplane would have missed the mountain/tree tops if the speedbrakes had been retracted during the escape attempt. However, the final report stated that if the flight crew had retracted the speedbrakes one second after initiating the escape maneuver, the airplane could have been climbing through a position that was 150 feet above the initial impact point. Because the airplane would have continued to climb and had the potential to increase its rate of climb, it might well have cleared the trees at the top of the mountain.

Aftermath

Scavengers took engine thrust reversers, cockpit avionics, and other components from the crashed 757, using Colombian military and private helicopters to go to and from the crash site. Many of the stolen components re-appeared as unapproved aircraft parts on the black market in Greater Miami parts brokers. In response, the airline published a 14-page list stating all of the parts missing from the crashed aircraft. The list included the serial numbers of all the parts.

In 1997 U.S. District Judge Stanley Marcus ruled that the pilots had committed “willful misconduct”; the ruling applied to American Airlines, which represented the deceased pilots. The judge’s ruling was subsequently reversed in June 1999 by the U.S. Court of Appeals in Atlanta, which also overturned the jury verdict and declared that the judge in the case was wrong in issuing a finding of fault with the pilots, a role which should have been reserved for the jury only.

American Airlines settled numerous lawsuits brought against it by the families of the victims of the accident. American Airlines filed a “third-party complaint” lawsuit for contribution against Jeppesen and Honeywell, which made the navigation computer database and failed to include the coordinates of Rozo under the identifier “R”; the case went to trial in United States District Court for the Southern District of Florida in Miami. At the trial, American Airlines admitted that it bore some legal responsibility for the accident. Honeywell and Jeppesen each contended that they had no legal responsibility for the accident. In June 2000, the jury found that Jeppesen was 30 percent at fault for the crash, Honeywell was 10 percent at fault, and American Airlines was 60 percent at fault.

An enhanced ground proximity warning system was introduced in 1996, which could have prevented the accident.

Since 2002, all planes with more than six passengers are required to have an advanced terrain awareness warning system. No aircraft fitted with a TAWS/EGPWS suffered a controlled flight into terrain accident until July 28, 2010, when Airblue Flight 202 crashed into the Margalla Hills, Pakistan.

As of September 2016, American Airlines still operates the Miami-Cali route, but as American Airlines Flight 921 and using an Airbus A319.

Crash investigation and final report

The crash was investigated by the Special Administrative Unit of Civil Aeronautics (Aeronáutica Civil) of the Republic of Colombia, with assistance from the U.S. National Transportation Safety Board (U.S. NTSB) as well as other parties, including the U.S. Federal Aviation Administration, Allied Pilots Association, American Airlines, Boeing Commercial Airplane Group and Rolls Royce Engines.

The Aeronáutica Civil prepared a final report of its investigation in September 1996, which was released through the U.S. NTSB.

In its report, the Aeronáutica Civil determined the following probable causes of the accident:

The flight crew’s failure to adequately plan and execute the approach to runway 19 at SKCL and their inadequate use of automation.

Failure of the flightcrew to discontinue the approach into Cali, despite numerous cues alerting them of the inadvisability of continuing the approach.

The lack of situational awareness of the flightcrew regarding vertical navigation, proximity to terrain, and the relative location of critical radio aids.

Failure of the flight crew to revert to basic radio navigation at the time when the FMS-assisted navigation became confusing and demanded an excessive workload in a critical phase of the flight.

In addition, the Aeronáutica Civil determined that the following factors contributed to the accident:

The flight crew’s ongoing efforts to expedite their approach and landing in order to avoid potential delays.

The flight crew’s execution of the GPWS escape maneuver while the speedbrakes remained deployed.

FMS logic that dropped all intermediate fixes from the display(s) in the event of execution of a direct routing.

FMS-generated navigational information that used a different naming convention from that published in navigational charts.

The Aeronáutica Civil’s report also included a variety of safety-related recommendations to the following parties (number of individual recommendations in parentheses):